Merge tag 'driver-core-4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git...

[cascardo/linux.git] / drivers / i2c / busses / i2c-i801.c

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 08847e8..eb3627f 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -146,6 +146,7 @@
 #define SMBHSTCFG_HST_EN       1
 #define SMBHSTCFG_SMB_SMI_EN   2
 #define SMBHSTCFG_I2C_EN       4
+#define SMBHSTCFG_SPD_WD       0x10
 
 /* TCO configuration bits for TCOCTL */
 #define TCOCTL_EN              0x0100
@@ -865,9 +866,16 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
                block = 1;
                break;
        case I2C_SMBUS_I2C_BLOCK_DATA:
-               /* NB: page 240 of ICH5 datasheet shows that the R/#W
-                * bit should be cleared here, even when reading */
-               outb_p((addr & 0x7f) << 1, SMBHSTADD(priv));
+               /*
+                * NB: page 240 of ICH5 datasheet shows that the R/#W
+                * bit should be cleared here, even when reading.
+                * However if SPD Write Disable is set (Lynx Point and later),
+                * the read will fail if we don't set the R/#W bit.
+                */
+               outb_p(((addr & 0x7f) << 1) |
+                      ((priv->original_hstcfg & SMBHSTCFG_SPD_WD) ?
+                       (read_write & 0x01) : 0),
+                      SMBHSTADD(priv));
                if (read_write == I2C_SMBUS_READ) {
                        /* NB: page 240 of ICH5 datasheet also shows
                         * that DATA1 is the cmd field when reading */
@@ -1573,6 +1581,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
                /* Disable SMBus interrupt feature if SMBus using SMI# */
                priv->features &= ~FEATURE_IRQ;
        }
+       if (temp & SMBHSTCFG_SPD_WD)
+               dev_info(&dev->dev, "SPD Write Disable is set\n");
 
        /* Clear special mode bits */
        if (priv->features & (FEATURE_SMBUS_PEC | FEATURE_BLOCK_BUFFER))